Main characteristics of the population
| Variable | N | Controls | Cases | P value* |
| N=525 | N=525 | |||
| Median (p10–p90) or N (%) | Median (p10–p90) or N (%) | |||
| Age (years) | 1050 | 40 (31–45) | 40 (31–45) | 0.06 |
| Age at menarche (years) | 1050 | 12 (10–15) | 12 (11–15) | 0.93 |
| Pregnancy ever | 911 | 478 (91) | 433 (84) | <0.0001 |
| Age at first full-term pregnancy† | 908 | <0.0001 | ||
| <20 | 180 (37.7) | 123 (28.5) | ||
| 20–25 | 174 (36.5) | 128 (29.7) | ||
| ≥25 | 123 (25.8) | 180 (41.8) | ||
| Age at first full-term pregnancy†(years) | 908 | 21 (16–29) | 23 (17–33) | <0.0001 |
| Age at last full-term pregnancy† (years) | 908 | 28 (22–36) | 30 (22–36) | 0.05 |
| Number of children | 1036 | <0.0001 | ||
| 0 | 47 (9.1) | 92 (17.8) | ||
| 1 | 112 (21.6) | 157 (30.4) | ||
| ≥2 | 360 (69.3) | 268 (51.8) | ||
| Ever breast feed, for parous women | 911 | 443 (92.7) | 383 (88.5) | <0.0001 |
| Cumulated duration of breast feeding† ≥12 months, | 911 | 313 (65.5) | 200 (46.1) | <0.0001 |
| History of benign breast disease | 1050 | 66 (12.6) | 191 (36.4) | <0.0001 |
| Family history of breast cancer | 1050 | 23 (4.4) | 33 (6.3) | 0.18 |
| Daily alcohol intake‡ (g/day) | 898 | 0.92 (0.05–4.95) | 0.83 (0.04–5.53) | 0.15 |
| Daily physical activity§ (hours/day) | 1050 | 3.6 (0.93–8.9) | 2.0 (0.36–8.4) | <0.0001 |
| Education level | 1050 | <0.0001 | ||
| ≤primary school (low) | 103 (19.6) | 65 (12.4) | ||
| secondary school (medium) | 286 (54.5) | 253 (48.2) | ||
| >secondary school (high) | 136 (25.9) | 207 (39.4) | ||
| Ever smoker (yes) | 530 | 285 (54.3) | 245 (46.7) | 0.009 |
| Anthropometry | ||||
| Height (m) | 1047 | 1.56 (1.50–1.65) | 1.57 (1.49–1.66) | 0.003 |
| Weight (kg) | 1049 | 68 (55–89) | 64 (52–80) | <0.0001 |
| BMI (kg/m²) | 1047 | 28.1 (22.3–36.2) | 26.1 (20.9–32.6) | <0.0001 |
| Energy intake and UPF¶ | ||||
| Energy (kcal) | 1050 | 2694 (1642–4732) | 2853 (1790–4672) | 0.09 |
| Energy (kcal) for NOVA 1 | 1050 | 1314 (736–2427) | 1372 (801–2472) | 0.25 |
| Energy (kcal) for NOVA 2 | 1050 | 102 (35–289) | 102 (27–247) | 0.16 |
| Energy (kcal) for NOVA 3 | 1050 | 463 (208-893) | 544 (236–997) | 0.09 |
| Energy (kcal) for NOVA 4 | 1050 | 641 (273–1599) | 729 (322–1449) | 0.23 |
| Biomarkers measured in blood | ||||
| Plasma industrial trans-fatty acids (%) | 284 | 0.27 (0.16–0.49) | 0.29 (0.16–0.57) | 0.05 |
| Tumour characteristics | ||||
| Hormone receptor status** | 332‡‡ | |||
| Oestrogen receptor positive | – | 240 (72) | ||
| Progesterone receptor positive | – | 230 (69) | ||
| HER2 positive | – | 56 (15) | ||
| Triple negative: ER−/PR−/HER2− | – | 70 (21) | ||
| Of which Basal-like†† | – | 61 (18) |
*P value Wilcoxon test from logistic regression conditional on matching factors.
†Among parous women only.
‡Among consumers.
§Daily moderate intensity physical activity.
¶NOVA group 1: Unprocessed or minimally processed foods; NOVA group 2: Processed culinary ingredients, NOVA group 3: Processed foods; NOVA group 4: Ultra-processed food and drink products.
**Immunohistochemistry is so far available for 332 cases. Percentages given for tumour characteristics are based on these 332 cases. Receptors status presented irrespective of other receptors.
††Basal-like: (TN and EGFR +and/or CK5/6+).
BMI, body mass index; CK5/6, cytokeratin 5/6; EGFR, epidermal growth factor receptor; ER, oestrogen receptor; HER2, human epidermal growth factor receptor 2; PR, progesterone receptor; TN, triple negative; UPF, ultra-processed foods.